How would you plan for family stay of 8?

How would you plan a family reunion of 8 multi-generational people? There is a family of 4, with two children under 6. My mother and I, which we will probably room together. And my father.

I just planned a vacation for my mother and I for October, but I was discussing we should try to plan something for the WHOLE family, including two young girls who want everything PRINCESS! But I have no idea how to go about something that large!

We'd probably want to stay around $5000, not including airfare. I have no idea how'd we room at Disney, either on-site or off. I imagine we'd try for Free Dining in September, if possible. I can imagine that the food savings for a family of 8 would outweigh any room discount.

It's kinda important that my mother and I have a room to ourselves, since she separated from my father and prefers to have her own private space.

My thought is to book rooms separately rather than suites? Has anyone done this before? I'm rather intimidated to plan this.

Help me with the math.
Family of four = 4
You and mom= 2
Dad= 1
I get 7. Who is the 8th? Does dad have a plus 1?.

If your budget is only $5,000 then I would think you'd be looking at value rooms. Tickets alone, for 7 people for 7 days would be just under half of that budget. Three standard rooms would be around $2,100 or so If you went in Sept for 7 nights. So that doesn't leave much room for food or souvenirs. You would have to have free dining (and no TS meals) to stay on budget.
You could find cheaper accommodation off site, but would have to add in car rental (possibly 2 cars), gas, parking fees and possibly resort fees as well.

$5,000 will be tough to pull off for 8 people if you're talking a week. We used to go as a party of 8 during free dining days (before we became DVC members) and it would run us just over $5,000 staying in a moderate resort with the free DDP (includes 1 table service meal).

If your dad must be apart from your mom there is no way to do this other than separate rooms.

Remember for free dining you have to pay rack rate for the room. And if you pick the values on free dining, you get the quick service plan free. You'd have to pay to upgrade quick service to regular plan if what you really want is the regular plan. You may want to shoot for a moderate. It will be tough to get that in under $5000 for 3 rooms. Or is that $5000 total for the whole trip? If that's the case, you'll have issues.

What's the deal with mom and dad? Are they OK eating together, touring together?